Quick-clamping cell



United States Patent Inventor Herbert H. Loefiler I Arlington,Massachusetts Appl. No. 789,881 Filed 1 Jan. 8,1969 Patented Nov. 3,1970 Assignee Amicon Corporation Lexington, Massachusetts a corporationof Massachusetts QUlCK-CLAMPING CELL 7 Claims, 4 Drawing Figs.

[1.8. CI. 220/4, 220/55, 292/256 int. Cl. B6Sd 7/24, 865d 45/06 Field ofSearch 220/4.55, 55.1, 556, (D, E, T); 215/86, 87, 88; 292/256, 256.69,256.75

[56] References Cited UNITED STATES PATENTS 2,518,298 8/1950 Erickson292/256X 2,691,111 10/1954 Minnich 2l5/88X 2,737,198 3/1956 Elliott220/556X 3,107,600 10/1963 Brun-Buisson 220/55.7X

Primary Examiner--George E. Lowrance Attorney-R. W. Furlong ABSTRACT: Aquick-opening process vessel with a novel, overcenter, toggle-typeclosure assembly wherein a very high mechanical advantage is achieved incompressing the vessel QUICK-CLAMPING can.

BACKGROUND OF THE INVENTION In the manufacture of closed, processvessels for use in processing liquids and other chemicals, it has beenthe practice to use a plurality of bolt-type fasteners to achieve asuitable sealing of the vessels. Some problems associated with the useof process vessels are (l) difficulty in cleaning, (2) hightime-consumption in opening or closing, (3) difficulty in obtaining auniform seal around the perimeter of the vessel, and (4) presentation ofa relatively unsightly object on a laboratory bench. Nevertheless, therehave been no wholly satisfactory substitutes for these prior art devicesand they are still widely used in both laboratory and large-scaleoperations.

Moreover, when transparent process vessels are used to follow visualmonitoring of the reactants, prior art devices do not provide aconvenient display surface for the display of operating instructions,supplierss name, or the like. This is a particular problem when thevessel is utilized as an ultrafiltration cell wherein careful attentionmust be given to the liquid level by an attendant who may be chargedwith watching a number of such cells.

SUMMARY OF THE INVENTION Therefore, it is an object of the invention toprovide a quick-opening process vessel which has relatively few partsand is easily and rapidly taken apart for cleaning.

Another object of the invention is'to provide such a vessel which isadequately sealed for accomodating moderate operating pressurestherewithin.

Another object of the invention is to provide an improved closureassembly for usewith such quick-opening process vessels.

Still another object of the invention is to provide a transparent vesselwhich has a convenient display surface associated with the closingmechanism thereof.

Another object of the invention is to provide a closure which assuresthe optimum mechanical advantage will be applied to closing anultrafiltration cell at precisely the time in the closing cycle thatsuch advantage is required, yet with minimum strain exerted on themembrane being sealed.

Other objects of the invention will be obvious to those skilled in theart on reading this specification.

The above objects have been substantially achieved by the constructionof a quick-opening vessel wherein a cylindrical reservoir is resilientlyheld between two end caps which end caps have positioning means such asgrooves or slots therein for receiving a novel closure assembly. Thisclosure assembly comprises a lower closure member for engaging apositioning slot in the lower end cap, and a toggle lever which isadapted for engagement with a locking groove in the upper-cap member.The toggle lever is pivotally connected to side bars which join theaforesaid lower member and toggle lever at a point proximate the bottomof thetoggle lever. Stop means is provided for limiting the movement ofthe lever at the overcenter position required to maintain thecompression on the cylinder.

At least one end cap is removable from the cylinder, although for manyapplications each end cap may be made removable. A compressible sealingmeans such as an O-ring is preferably utilized to effect a seal betweena removable end cap and the wall of the cylinder. The overcenter-typetoggle action exerted by the closing lever is particularly advantageouswith respect to obtaining the optimum compressive seal between the endcaps and cylinder, because the toggle action is designed to give maximummechanical advantage at the time maximum compression on the seal isreached. This advantage is achieved and tends to infinity as thehorizontal movement of the toggle lever becomes predominant during thelocking action. This action is particularly advantageous when utilizedwith ultrafiltration cells because it assures that membranes beingedge-sealed by the higher compressive forces will be subjected tominimum strain as the sealing action is completed.

One important use of the apparatus of the invention is withultrafiltration cells wherein it is highly desirable that the process bevisible to the operator. In such apparatus the toggle lever may form abroad planar surface suitable for display of instructional orpromotional material without the need of placing vision-blocking labelson the cylinder itself. Moreover, when the apparatus of the invention isused as an ultratiltration cell, the ultrafiltration membrane isnormally protected from being cut during the compressive sealing actionby the low strain rate used to achieve the final sealing of the membraneby an O-ring sealing means encircling the edge thereof.

ILLUSTRATIVE EXAMPLE OF THE INVENTION FIG. 1 is a view partially insection of the quick-clamping cell of the invention.

FIG. 2 is a view of the cell shown in FIG. I but taken at angletherefrom.

FIG. 3 is a plan view of the quick-clamping cell of the invention.

FIG. 4 shows detail of the pivot.

Referring to FIGS. 1 and 2, it is seen that quick-clamping precessingvessel 10 comprises a transparent reservoir 12 formed ofa cylinder 13,an upper end cap member 14, a lower end cap member 16, each of said endcaps being separated from said reservoir 12 by seal means comprised ofresilient elastomeric O-rings 18.

Upper end cap 14 comprises means to receive a pressure relief valve 20and means to hold an agitator shaft 22. A magnetic stirring bar 24 isrotably mounted on shaft 22, by bracket 26, for actuation by a magneticstirring table (not shown) of the type known in the art. Upper capmember 14 includes a stop means 28 comprised of an inclined support wall30 and also includes a locking groove 32 at the bottom terminal of wall30.

Lower cap member 16 comprises a block 33 into which has been cut apositioning slot 34 thereby forming means to position a lower horizontalmember 37 of a unitary, U-shaped clamp 38 of a closure assembly 39. Theelongated side bars of clamp 38 comprise apertures 42 into which studs44 of toggle lever 46 are pivotally positioned proximate the bottom ofthe toggle lever. Studs 44 have a rounded surface 45 to facilitate thepivoted movement of the studs in apertures 43. Toggle lever 46 comprisesa planar display surface 48 and forms means for moving closure assemblyfrom a closed tight position to an open or loose position.

By pulling outwardly on toggle lever 46, closure assembly 38 may bereadily removed from the vessel. The assembly remains in one piece andthus may be readily replaced by simply bearing up upon toggle lever 46to lock it into groove 32. Each of the end caps 14 and 16 and reservoirI2 may be individually washed, yet quickly reassembled into an operableunit utilizing closure assembly 39.

Sealed between lower O-rings l8 and bottom end cap 16 is anultrafiltration membrane 50, e.g. a membrane of the type sold by AmiconCorporation under the trade designation XM- 50. The compression on themembrane by cylinder 13's bearing on lower O-ring 18 seals the edges ofthe membrane against lower end-cap member 16, End cap 16 comprises agroove 52 therein and a conduit 54 therethrough which groove and conduitallow ultrnftltrate to be discharged through discharge line 56. Mostultrnliltration membranes will have a relatively porous backing memberwhich allows the ultrafiltrate to seek the groove 52 without the aid ofan intervening porous plate member. However, such a plate member may beused where the membrane itself comprises no such porous backing memberor is too fragile to be self-supporting.

When the end caps are fabricated of relatively low modulus materials(e.g. from thermoplastics such as nylon, the polyaldehyde sold under thetrade designation Delrin by E. l. Du- Pont de Nemours and Co., Inc.,polytetrafluoroethylene, and the like), a particular safety feature canbe built into the apparatus inasmuch as such materials will deflectenough under moderately high pressures, say to 200 p.s.i.g., to breakthe O-ring seal and allow escape of gas from the apparatus. Plasticmaterials with moduli below about 450,000 p.s.i. (ASTM D638) are mostadvantageous when such a "built-in relief valve feature is desired.

lclaim:

1. A quick-opening processing vessel comprising a cylinder; an upper capmember and a lower cap member, each said cap member being held in snugrelationship to said cylinder by a closure assembly adapted forengagement with a locking groove in said upper cap member and apositioning slot in said lower cap member; said closure assemblycomprising a lower member engaging said positioning slot, a toggle leverengaging said locking groove, side bars connection corresponding sidesof said lower member and said toggle lever, said connection between saidside bars and said toggle lever being a pivotal connection proximate oneend of said toggle lever whereby said closure assembly may be actuatedby toggle action to maintain said pressure vessel in a closed positionor to loosen to allow disassembly of said pressure vessel; and stopmeans mounted adjacent said clamping lever to provide means for limitingits movement beyond that required to maintain said vessel in a closedposition.

2. A vessel as defined in claim 3 wherein said cylinder is transparentcylinder and wherein said toggle lever comprises a planar surfacesuitable for display of descriptive material.

3. A vessel as defined in claim 1 wherein resilient, elastomeric O-ringseal members are compressed between said cylinder and each of said capmembers which members are fabricated from a relatively-low modulusmaterial, thereby providing a built-in, over-pressure release means.

4. A vessel as defined in claim 1 wherein said lower cap comprises aconduit therein which provides means for removing liquid from saidreservoir.

5. A vessel as defined in claim 3 comprising a semipermeable membranepositioned between said O-ring seal members and said lower cap.

6. A vessel as defined in claim 1 wherein said stop means is anintergral part of said upper cap member.

7. A vessel as defined in claim 1 wherein said lower member and saidside members are formed of a single U-shaped element.

